1 /*- 2 * Copyright (c) 2006 The FreeBSD Project. 3 * Copyright (c) 2015 Andrey V. Elsukov <ae@FreeBSD.org> 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26 * SUCH DAMAGE. 27 * 28 * $FreeBSD$ 29 */ 30 31 #include "opt_inet.h" 32 #include "opt_inet6.h" 33 34 #include <sys/param.h> 35 #include <sys/systm.h> 36 #include <sys/kernel.h> 37 #include <sys/malloc.h> 38 #include <sys/mbuf.h> 39 #include <sys/module.h> 40 #include <machine/bus.h> 41 #include <sys/rman.h> 42 #include <sys/socket.h> 43 #include <sys/sockio.h> 44 #include <sys/sysctl.h> 45 46 #include <net/if.h> 47 #include <net/if_var.h> 48 #include <net/if_clone.h> 49 #include <net/if_types.h> 50 #include <net/pfil.h> 51 #include <net/route.h> 52 #include <net/netisr.h> 53 #include <net/bpf.h> 54 #include <net/vnet.h> 55 56 #include <netinet/in.h> 57 #include <netinet/in_systm.h> 58 #include <netinet/ip.h> 59 #include <netinet/ip_var.h> 60 #include <netinet/in_var.h> 61 62 #ifdef INET6 63 #include <netinet/ip6.h> 64 #include <netinet6/ip6_var.h> 65 #endif 66 67 #include <netipsec/ipsec.h> 68 #include <netipsec/xform.h> 69 70 #define ENCMTU (1024+512) 71 72 /* XXX this define must have the same value as in OpenBSD */ 73 #define M_CONF 0x0400 /* payload was encrypted (ESP-transport) */ 74 #define M_AUTH 0x0800 /* payload was authenticated (AH or ESP auth) */ 75 #define M_AUTH_AH 0x2000 /* header was authenticated (AH) */ 76 77 struct enchdr { 78 u_int32_t af; 79 u_int32_t spi; 80 u_int32_t flags; 81 }; 82 struct enc_softc { 83 struct ifnet *sc_ifp; 84 }; 85 static VNET_DEFINE(struct enc_softc *, enc_sc); 86 #define V_enc_sc VNET(enc_sc) 87 static VNET_DEFINE(struct if_clone *, enc_cloner); 88 #define V_enc_cloner VNET(enc_cloner) 89 90 static int enc_ioctl(struct ifnet *, u_long, caddr_t); 91 static int enc_output(struct ifnet *, struct mbuf *, 92 const struct sockaddr *, struct route *); 93 static int enc_clone_create(struct if_clone *, int, caddr_t); 94 static void enc_clone_destroy(struct ifnet *); 95 static int enc_add_hhooks(struct enc_softc *); 96 static void enc_remove_hhooks(struct enc_softc *); 97 98 static const char encname[] = "enc"; 99 100 /* 101 * Before and after are relative to when we are stripping the 102 * outer IP header. 103 */ 104 static VNET_DEFINE(int, filter_mask_in) = IPSEC_ENC_BEFORE; 105 static VNET_DEFINE(int, bpf_mask_in) = IPSEC_ENC_BEFORE; 106 static VNET_DEFINE(int, filter_mask_out) = IPSEC_ENC_BEFORE; 107 static VNET_DEFINE(int, bpf_mask_out) = IPSEC_ENC_BEFORE | IPSEC_ENC_AFTER; 108 #define V_filter_mask_in VNET(filter_mask_in) 109 #define V_bpf_mask_in VNET(bpf_mask_in) 110 #define V_filter_mask_out VNET(filter_mask_out) 111 #define V_bpf_mask_out VNET(bpf_mask_out) 112 113 static SYSCTL_NODE(_net, OID_AUTO, enc, CTLFLAG_RW, 0, "enc sysctl"); 114 static SYSCTL_NODE(_net_enc, OID_AUTO, in, CTLFLAG_RW, 0, "enc input sysctl"); 115 static SYSCTL_NODE(_net_enc, OID_AUTO, out, CTLFLAG_RW, 0, "enc output sysctl"); 116 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_filter_mask, 117 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_in), 0, 118 "IPsec input firewall filter mask"); 119 SYSCTL_INT(_net_enc_in, OID_AUTO, ipsec_bpf_mask, 120 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_in), 0, 121 "IPsec input bpf mask"); 122 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_filter_mask, 123 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(filter_mask_out), 0, 124 "IPsec output firewall filter mask"); 125 SYSCTL_INT(_net_enc_out, OID_AUTO, ipsec_bpf_mask, 126 CTLFLAG_RW | CTLFLAG_VNET, &VNET_NAME(bpf_mask_out), 0, 127 "IPsec output bpf mask"); 128 129 static void 130 enc_clone_destroy(struct ifnet *ifp) 131 { 132 struct enc_softc *sc; 133 134 sc = ifp->if_softc; 135 KASSERT(sc == V_enc_sc, ("sc != ifp->if_softc")); 136 137 enc_remove_hhooks(sc); 138 bpfdetach(ifp); 139 if_detach(ifp); 140 if_free(ifp); 141 free(sc, M_DEVBUF); 142 V_enc_sc = NULL; 143 } 144 145 static int 146 enc_clone_create(struct if_clone *ifc, int unit, caddr_t params) 147 { 148 struct ifnet *ifp; 149 struct enc_softc *sc; 150 151 sc = malloc(sizeof(struct enc_softc), M_DEVBUF, 152 M_WAITOK | M_ZERO); 153 ifp = sc->sc_ifp = if_alloc(IFT_ENC); 154 if (ifp == NULL) { 155 free(sc, M_DEVBUF); 156 return (ENOSPC); 157 } 158 if (V_enc_sc != NULL) { 159 if_free(ifp); 160 free(sc, M_DEVBUF); 161 return (EEXIST); 162 } 163 V_enc_sc = sc; 164 if_initname(ifp, encname, unit); 165 ifp->if_mtu = ENCMTU; 166 ifp->if_ioctl = enc_ioctl; 167 ifp->if_output = enc_output; 168 ifp->if_softc = sc; 169 if_attach(ifp); 170 bpfattach(ifp, DLT_ENC, sizeof(struct enchdr)); 171 if (enc_add_hhooks(sc) != 0) { 172 enc_clone_destroy(ifp); 173 return (ENXIO); 174 } 175 return (0); 176 } 177 178 static int 179 enc_output(struct ifnet *ifp, struct mbuf *m, const struct sockaddr *dst, 180 struct route *ro) 181 { 182 183 m_freem(m); 184 return (0); 185 } 186 187 static int 188 enc_ioctl(struct ifnet *ifp, u_long cmd, caddr_t data) 189 { 190 191 if (cmd != SIOCSIFFLAGS) 192 return (EINVAL); 193 if (ifp->if_flags & IFF_UP) 194 ifp->if_drv_flags |= IFF_DRV_RUNNING; 195 else 196 ifp->if_drv_flags &= ~IFF_DRV_RUNNING; 197 return (0); 198 } 199 200 /* 201 * One helper hook function is used by any hook points. 202 * + from hhook_type we can determine the packet direction: 203 * HHOOK_TYPE_IPSEC_IN or HHOOK_TYPE_IPSEC_OUT; 204 * + from hhook_id we can determine address family: AF_INET or AF_INET6; 205 * + udata contains pointer to enc_softc; 206 * + ctx_data contains pointer to struct ipsec_ctx_data. 207 */ 208 static int 209 enc_hhook(int32_t hhook_type, int32_t hhook_id, void *udata, void *ctx_data, 210 void *hdata, struct osd *hosd) 211 { 212 struct enchdr hdr; 213 struct ipsec_ctx_data *ctx; 214 struct enc_softc *sc; 215 struct ifnet *ifp, *rcvif; 216 struct pfil_head *ph; 217 int pdir; 218 219 sc = (struct enc_softc *)udata; 220 ifp = sc->sc_ifp; 221 if ((ifp->if_flags & IFF_UP) == 0) 222 return (0); 223 224 ctx = (struct ipsec_ctx_data *)ctx_data; 225 /* XXX: wrong hook point was used by caller? */ 226 if (ctx->af != hhook_id) 227 return (EPFNOSUPPORT); 228 229 if (((hhook_type == HHOOK_TYPE_IPSEC_IN && 230 (ctx->enc & V_bpf_mask_in) != 0) || 231 (hhook_type == HHOOK_TYPE_IPSEC_OUT && 232 (ctx->enc & V_bpf_mask_out) != 0)) && 233 bpf_peers_present(ifp->if_bpf) != 0) { 234 hdr.af = ctx->af; 235 hdr.spi = ctx->sav->spi; 236 hdr.flags = 0; 237 if (ctx->sav->alg_enc != SADB_EALG_NONE) 238 hdr.flags |= M_CONF; 239 if (ctx->sav->alg_auth != SADB_AALG_NONE) 240 hdr.flags |= M_AUTH; 241 bpf_mtap2(ifp->if_bpf, &hdr, sizeof(hdr), *ctx->mp); 242 } 243 244 switch (hhook_type) { 245 case HHOOK_TYPE_IPSEC_IN: 246 if (ctx->enc == IPSEC_ENC_BEFORE) { 247 /* Do accounting only once */ 248 if_inc_counter(ifp, IFCOUNTER_IPACKETS, 1); 249 if_inc_counter(ifp, IFCOUNTER_IBYTES, 250 (*ctx->mp)->m_pkthdr.len); 251 } 252 if ((ctx->enc & V_filter_mask_in) == 0) 253 return (0); /* skip pfil processing */ 254 pdir = PFIL_IN; 255 break; 256 case HHOOK_TYPE_IPSEC_OUT: 257 if (ctx->enc == IPSEC_ENC_BEFORE) { 258 /* Do accounting only once */ 259 if_inc_counter(ifp, IFCOUNTER_OPACKETS, 1); 260 if_inc_counter(ifp, IFCOUNTER_OBYTES, 261 (*ctx->mp)->m_pkthdr.len); 262 } 263 if ((ctx->enc & V_filter_mask_out) == 0) 264 return (0); /* skip pfil processing */ 265 pdir = PFIL_OUT; 266 break; 267 default: 268 return (EINVAL); 269 } 270 271 switch (hhook_id) { 272 #ifdef INET 273 case AF_INET: 274 ph = &V_inet_pfil_hook; 275 break; 276 #endif 277 #ifdef INET6 278 case AF_INET6: 279 ph = &V_inet6_pfil_hook; 280 break; 281 #endif 282 default: 283 ph = NULL; 284 } 285 if (ph == NULL || !PFIL_HOOKED(ph)) 286 return (0); 287 /* Make a packet looks like it was received on enc(4) */ 288 rcvif = (*ctx->mp)->m_pkthdr.rcvif; 289 (*ctx->mp)->m_pkthdr.rcvif = ifp; 290 if (pfil_run_hooks(ph, ctx->mp, ifp, pdir, NULL) != 0 || 291 *ctx->mp == NULL) { 292 *ctx->mp = NULL; /* consumed by filter */ 293 return (EACCES); 294 } 295 (*ctx->mp)->m_pkthdr.rcvif = rcvif; 296 return (0); 297 } 298 299 static int 300 enc_add_hhooks(struct enc_softc *sc) 301 { 302 struct hookinfo hki; 303 int error; 304 305 error = EPFNOSUPPORT; 306 hki.hook_func = enc_hhook; 307 hki.hook_helper = NULL; 308 hki.hook_udata = sc; 309 #ifdef INET 310 hki.hook_id = AF_INET; 311 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 312 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], 313 &hki, HHOOK_WAITOK); 314 if (error != 0) 315 return (error); 316 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 317 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], 318 &hki, HHOOK_WAITOK); 319 if (error != 0) 320 return (error); 321 #endif 322 #ifdef INET6 323 hki.hook_id = AF_INET6; 324 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 325 error = hhook_add_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], 326 &hki, HHOOK_WAITOK); 327 if (error != 0) 328 return (error); 329 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 330 error = hhook_add_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], 331 &hki, HHOOK_WAITOK); 332 if (error != 0) 333 return (error); 334 #endif 335 return (error); 336 } 337 338 static void 339 enc_remove_hhooks(struct enc_softc *sc) 340 { 341 struct hookinfo hki; 342 343 hki.hook_func = enc_hhook; 344 hki.hook_helper = NULL; 345 hki.hook_udata = sc; 346 #ifdef INET 347 hki.hook_id = AF_INET; 348 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 349 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET], &hki); 350 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 351 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET], &hki); 352 #endif 353 #ifdef INET6 354 hki.hook_id = AF_INET6; 355 hki.hook_type = HHOOK_TYPE_IPSEC_IN; 356 hhook_remove_hook(V_ipsec_hhh_in[HHOOK_IPSEC_INET6], &hki); 357 hki.hook_type = HHOOK_TYPE_IPSEC_OUT; 358 hhook_remove_hook(V_ipsec_hhh_out[HHOOK_IPSEC_INET6], &hki); 359 #endif 360 } 361 362 static void 363 vnet_enc_init(const void *unused __unused) 364 { 365 366 V_enc_sc = NULL; 367 V_enc_cloner = if_clone_simple(encname, enc_clone_create, 368 enc_clone_destroy, 1); 369 } 370 VNET_SYSINIT(vnet_enc_init, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 371 vnet_enc_init, NULL); 372 373 static void 374 vnet_enc_uninit(const void *unused __unused) 375 { 376 377 if_clone_detach(V_enc_cloner); 378 } 379 VNET_SYSUNINIT(vnet_enc_uninit, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY, 380 vnet_enc_uninit, NULL); 381 382 static int 383 enc_modevent(module_t mod, int type, void *data) 384 { 385 386 switch (type) { 387 case MOD_LOAD: 388 case MOD_UNLOAD: 389 break; 390 default: 391 return (EOPNOTSUPP); 392 } 393 return (0); 394 } 395 396 static moduledata_t enc_mod = { 397 "if_enc", 398 enc_modevent, 399 0 400 }; 401 402 DECLARE_MODULE(if_enc, enc_mod, SI_SUB_PROTO_IFATTACHDOMAIN, SI_ORDER_ANY); 403